During welding operations, electrode tips are subject to wear, mushrooming, and general deformation. As tips wear they are subject to heat build-up and, given sufficient wear, electrode tips produce either poor welds or fail to weld at all. To prevent the conditions that effect adverse welding performance, electrode tips have commonly either been replaced or dressed. Replacing worn electrodes is often not only a time consuming, but a costly proposition; dressing electrode tips has been found to be not only a viable, but sensible alternative. A properly dressed electrode tip will result in not only reduced energy consumption, but uniform welds, reduced production and maintenance downtime and an extension of useful electrode life.
Typically, in the past, electrode tips have been dressed either by hand or with the use of an automatic electrode tip cutter. The difficulty with hand dressing of electrode tips is that the procedure lacks considerably in accuracy and the constant risk is run of removing too much tip material thereby reducing tip life or dressing the tips asymmetrically such that they no longer properly mate because the original shape of the tip has been lost.
Further, in hand dressing of electrode tips, machine downtime is a consideration of some magnitude and although various type ratchet apparatus have been employed, accuracy of the final dressed tip has suffered virtually to the same degree that is encountered with hand filing or sanding. Probably the best of the various alternatives to electrode tip dressing is the use of automatic cutters. Downtime is substantially reduced, the electrode tips do not have to be removed from the welding machine and the tips may be dressed with considerably more frequency and before the electrode face is seriously deformed.
A well dressed electrode tip provides more uniform current density, better welds and extended electrode life. Several types of electrode tip cutters have been employed in automatic dressers in the past. Essentially these are a blade type cutter and a flanged cone type cutter. This latter type cutter normally has sharpened edges, but is essentially solid in overall configuration. One of the problems encountered with the solid type cutters is that the end of the tool is difficult to resharpen and it is not readily adaptable to different types of dresser tip configurations.
Of the blade type cutters, adaptability to accommodate various tip shapes existed. The blades could also be removed for sharpening and were normally designed to float within a blade holder so that the electrode tip could be centered in the center of the cutter. Some adaptations have employed a cutter with three cutting surfaces although these were somewhat more difficult to sharpen. In the past some difficulty has been encountered in reinserting the cutters into the holder and as the number of blades on the cutter increased a certain amount of chatter was encountered which affected the dressing operation.